Treatment of Oil Contamination on Epoxy Floors

Common treatment materials include sodium hydroxide, sodium carbonate, silicates and phosphates.

Alkaline solution can be used to remove oil stains on the coating film after epoxy floor construction. Degreasing with alkaline liquid mainly relies on the saponification of alkali to eliminate grease and slight contaminants on the epoxy floor surface, so as to achieve surface purification. The higher the concentration of the alkaline solution, the more favorable the saponification reaction will be. It reduces the surface tension between oil stains and the solution, making degreasing easier.

For alkaline materials commonly used in cleaning oil stains on epoxy floor coatings, the essential requirements are: capable of dissolving grease, able to form high alkalinity, effective in dispersing colloidal substances, easy to rinse with water, good chemical stability, heat resistance, non-toxicity, and low corrosiveness. Due to low cost, simple operation and easy management, alkaline degreasing is suitable for mechanized construction and has been widely adopted in the industry.

Wiping method is the most commonly used cleaning approach. Various cleaning methods can be adopted according to different working conditions and the degree of oil contamination. Degreasing is usually the first procedure of surface treatment. For floors soaked in grease all year round, oil may still seep up from the base after the first degreasing, requiring secondary or multiple oil removal treatments.

For floor degreasing with alkaline solution, dip brushes, cleaning cloths, cotton yarn and other tools into alkaline liquid or mixed alkaline degreaser, then wipe and clean the oily surface. This is a manual operation with low efficiency and poor working conditions, yet it requires no special equipment, features low cost and flexible application.

It is generally used as a pre-treatment step for degreasing: first remove surface dust, debris and thick oil dirt, then perform alkaline degreasing. It should be noted that the concentration and operating temperature of the alkaline solution must not be excessively high. Labor protection must be strengthened to avoid alkali damage to the skin and eye cornea.

As for degreasing temperature, raising the temperature helps promote the saponification reaction, softens high-melting-point oil stains, and improves wetting and emulsification performance, thereby increasing degreasing efficiency and speed. However, excessively high temperature leads to high energy consumption. Large amounts of volatile substances will pollute the construction site air and worsen working conditions, and may even corrode the base surface. Most new-type degreasers specify the applicable temperature range, especially the upper limit, which must be strictly followed.

In terms of degreasing time, higher temperature and lighter oil contamination mean shorter degreasing time. Properly extending the treatment time can improve the cleaning effect. Nevertheless, overly long soaking will cause alkaline chemicals to be absorbed by micropores on the base surface, resulting in slight corrosion and passivation, and bringing difficulties to subsequent water rinsing.